Summary

I've had the desktop magnifier with an ancient glass tube of light that gets hot for decades and wanted to replace it for years, but never found what I wanted and it would never die. I saw another mod here a few weeks ago (https://www.thingiverse.com/thing:2757462
) and got inspired. It had a different mount and lens size though. This has a 5 inch lens that measures 126.3mm with a 4mm edge, and the mount is on top instead of the back. So I found a COB LED ring on ebay for $12.41 that's 140mm and assumed it would clear the lens or even hold it in place. It does clear it, but it's 5mm wide, so the I.D. is 130mm.

The top part was printed using a brim and supports (touching build plate) .

The screw holes are 2mm wide and 6mm deep for plastic screws. 8 for the ring, and 4 for the back. The ring is 2.5mm thick and the back is 4mm. So 8 2x8 and 4 2x10 at most. 2-3mm shorter would do fine.

The switch is a common mini rocker (20x12mm), and you'll need a 12V DC wall wart, and either a female barrel connector or cut and solder the wires directly. The LED came with a current limiter which can go on the other end since it's a bit bulky. I soldered the wires to the switch at the base of the lugs, and cut them down to make this as thin as I could. It only has 3mm of space in the back part.

Update: LED_Ring_v2 has no bevel so the lens fits tighter.
Added 10mm (actually 10.2mm to fit well) shaft option for some common cool mic booms. I just flip it upside down to use the mic.